Slide Pack 3a Flashcards
Winkler Growing Degree Days (GDD) math?
From April 1 to October 31, sum the amount that average daily temps exceed 50 degrees F
GDD established?
1944
Factors to consider with GDD?
1) Length of growing season - short vs long
2) Intensity of sunlight - higher with elevation -speeds ripening
3) Evapo-transporation (ET) water usage rate
4) Vineyard management
Soil texture refers to ?
Type, amount and size of clay, sand and silt particles
What can soil texture tell you?
1) how much water and nutrients soil can hold
2) how fast water will drain
3) how much air is in soil
4) How deep roots will go
5) Need for rootstock and what kind
Soil particles from largest to smallest?
Gravel, sand, silt, clay
Sandy soils made of what?
Large hard particles (silica) that drain rapidly
Sandy soil disadvantage?
Can lead to water stress in dryer regions
Sandy soil advantages?
1) Drains well in wetter climates
2) Soil draining reduces disease pressure
3) Low nutrients to moderate “green” growth
4) Generally resists Phylloxera attack thus allowing own rooted vines
Silt has finer texture than?
Sand
Silt has higher what than sand?
Water retention
Disadvantage of silt?
Can make soils too fertile for wine making (excessive green growth)
Disadvantage of clay soils?
1) Small particles tend to strongly hold onto water
2) Promotes waterlogging and disease of roots
Advantage of clay soils?
Clay soils tend to remain cooler benefiting grape vines in warmer regions
What grape varietal likes clay soils?
Nebbiolo
Too much clay makes it difficult for wine grape growing - T or F
True
What is a loamy soil?
Mixture of sand, clay and/or silt
Most agree that loamy soil is the best type of soil for grape growing - T or F
True
Advantages of loamy soil?
1) Sand promotes drainage
2) Silt and clay help contain water and nutrients
3) Generally lies in preferred pH range of 7
A crumbly loam mix of sand, silt, and clay offer the ideal soil type for drainage, moderate nutrition and balanced growth - T or F
True
Limestone soils are know for what?
Quality European winemaking in many famous regions
Limestone is formed from what?
Decomposed calcareous matter of sea life that once lived in ancient seas.
Advantages of limestone soils?
1) Good drainage in wet weather
2) Retains water in dry weather
3) Light color reflects sunlight for photosynthesis
Concern for limestone soil?
Has high pH which limits adsorption of certain nutrients and might bring a need for a rootstock
Volcanic soils are?
Soils with igneous and metamorphosed (from heated and transformed rock) constituents from long ago volcanos
Characteristics of volcanic soils?
1) Finely grained
2) Retain heat
3) Drain well
4) Typically neutral to acidic
Volcanic soils are rich in minerals like?
1) Iron
2) Calcium
3) Magnesium
4) Potassium
Volcanic soils being rich in minerals lead to?
Rich, ripe grapes and often higher alcohol wines
Where are volcanic soils found?
Most west coast wine regions with only certain areas in TX
What’s in common with AVA’s in Texas?
1) Generally west of Balcones fault
2) Higher and dryer and cooler nights than eastern portion of Texas
Two most recognized Texas AVA’s?
Texas High Plains and Texas Hill Country
AVA definition?
1) Designated wine grape-growing regions in the US
2) Distinguished by geographic features with
3) Boundaries defined by the TTB (Alcohol and Tobacco Tax and Trade Bureau of the United States Treasury)
Texas Hill Country AVA Facts?
1) Located centrally on Edwards Plateau
2) Largest AVA in Texas and one of the largest in US with 9 million acres
3) Contains two sub AVA’s
4) Wine tourism capital of Texas
5) 1991
Describe THC AVA
Includes many hills and steep canyons widely varying topography particularly on eastern slope caused by erosion of the Edwards Plateau
Cities within THC AVA?
Fredericksburg, Comfort, Mason, Burnet
THC elevation facts?
1) 1400 to 2300 ft
2) Highest elevation in north and west on Edwards Plateau
3) Lowest elevation in south and east just off eroded edge of the plateau
THC Rivers?
Llano, Colorado, Pedernales, Guadalupe, Blanco, Medina
THC Soil type facts?
58 soil types being clay loam, clay and sandy clay
THC clay soils are?
1 to 5 feet in depth over limestone, sandstone and granitic bedrock with a ph ranging from acid to alkaline 6.2 to 8.1 with an average pH 7.2
THC temperatures?
15 F to 105 F
Moderate diurnal fluctuations (20-25 F) with slow heat build up versus heat spikes
THC cumulative GDD?
4,700 to 6,000 based on April thru October but harvest is usually complete by end of August. Reduces effective GDD
THC last spring frost?
March 1st to April 15th
THC first freeze?
November 1st to 16th
THC freeze concerns?
Higher elevations have more freeze days but lower elevations can drain cold freezing temperatures in late spring
THC precipitation?
25-35 inches annual rainfall
THC red grape varieties?
1) Tempranillo
2) Cabernet
3) Mourvedre
4) Black Spanish
7) Tannat but #1 in yield
THC white grape varieties?
1) Viognier
2) Blanc du Bois
THC highest yield per acre?
1) Tannat
2) Malbec
3) Grenache
4) Tempranillo
Bell Mountain AVA facts?
1) First AVA - 1986
2) Named after Bell Mountain and winery
3) Smallest - 3200 acres
4) All within THC
5) Located just north of Fredericksburg on Rt 16 near Willow City
6) Overlaps new proposed AVA’s in Llano Uplift
Bell Mountain soils?
1) Mostly clay and sandy loams up to 7 ft deep
2) soil pH slightly acid to slightly alkaline
3) Sandy areas pH 6.6
4) Limestone soils pH 7.8
Describe Fredericksburg AVA?
1) Second AVA filed within Texas - 1988
2) Contained entirely within Gillespie County and THC AVA
3) 34,800 acres around city of Fredericksburg
4) Includes many wineries along Hwy 290 and Tx 16 south
Fredericksburg AVA soils?
1) Four soil types dominate
2) Mostly clayey and some silty loams up to 8 ft deep over limestone bedrock
3) pH neutral to alkaline - 7.1 to 8.2
Define Terroir?
The ability to describe the character of a wine region
How does an AVA get established?
1) Interested parties petition TTB
2) AVA must be distinguishable by geographic features and boundaries
What information is needed to establish AVA?
1) Name is locally or nationally known
2) Evidence boundaries are defined and legit
3) Historical and/or current information on grape or wine production is supported
4) Evidence grape growing conditions are distinctive
5) Narrative description of boundaries on USGS maps
